1.) Very cool.

2.) That ring is reducing a steady-state, rather specific signal. I have doubts about the practicality of lining cubicles with these and hoping for significant sound reduction, as noise is typically broader in frequencies than what was demonstrated. It could be quite useful for HVAC systems, though.

3.) This design may be suitable for pipes, but I am not clear on how well it would work in environments beyond tubes. Rooms have multiple surfaces for reflections/reverberation, and finding the perfect angles for cancellation could be quite challenging.

4.) Sounds that vary in loudness and timing may also be more challenging to block than the sound that was demo'ed. Those factors are often present in the louder, intermittent sounds that we have aversions to, so again the true practicality of the device is questionable to me.



Side note: their information about acoustics in architectural design seems a bit circumspect. They lost me at "Human speech ranges between 125 and 4,000 Hz" which is, put kindly, incorrect.